The specific aim of this proposal is to characterize the economic burden of keratoconus from the perspective of the patient and society. The proposed economic analysis will use data collected in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK), a multi-center (16 clinics), observational study funded by the National Eye Institute that characterized the prognosis in keratoconus and its impact on quality of life. The proposed analyses will evaluate data collected from the baseline examination and eight annual follow-up visits, including the Year 8 close-out examination that included questions specifically concerned with the economic burden of keratonconus. 967 CLEK patients (81% of the original CLEK cohort completed the close-out visit. We will conduct this economic evaluation in two parts. First, we will construct a decision model to describe the progression of keratoconus and related costs. Secondly, we will determine if disease progression is associated with economically significant events (automobile accidents, falls, and occupational accidents) that are known to be associated with impaired visual function. This proposed project will be the first to document the costs of care borne by patients with keratoconus. [unreadable] [unreadable] Population based studies of keratoconus have shown an incidence of two per 100,000 and prevalence to be 54.5 per 100,000, and it manifests relatively early in life substantially magnifying its public health impact. Marked reductions in vision-related quality of life were documented among CLEK patients, whose scores in most domains of the NEI-VFQ (including mental health and social function) were similar to those reported by patients with advanced macular degeneration (stages three and four) in the Age-Related Eye Disease Study. A survey of CLEK patients found less than half had health insurance coverage for the purchase of services and supplies related to their condition. This economic evaluation will provide health services researchers and patient advocates the evidence necessary to change insurance coverage policy as well as advocate for research funding to improve treatment. [unreadable] [unreadable] [unreadable]